July 16, 1993: Patrick Volkerding releases Slackware 1.00.
16 August, 1993: Ian Murdock announces that he wants to create a distro called Debian. No code is forthcoming.
15 September, 1993: Debian 0.01 ALPHA is 'released'.
17 October, 1993: Debian 0.02 ALPHA is 'released'.
02 November, 1993: Debian 0.03 ALPHA is 'released'.
05 November, 1993: Slackware 1.1.0 is released.
07 November, 1993: Debian 0.04 ALPHA is 'released'.
23 November, 1993: Debian 0.80 BETA is 'released' (limited beta).
28 November, 1993: Debian 0.81 BETA is 'released' (limited beta).
26 January, 1994: Debian 0.90 BETA is 'released' (public beta).
29 January, 1994: Debian 0.91 BETA is 'released' (public beta).
I keep hearing this 'only by a matter of weeks' line. It looks to me like the first public 'release' of Debian occurred in January of 1994, six months after the first release of Slackware. Or does anyone want to argue that Duke Nukem Forever came out in 1997?
Note that I'm giving Debian the benefit of the doubt here, by calling a 'public beta' a 'public release'.